1. Field of the Invention
The present invention relates generally to power over Ethernet (PoE) and, more particularly, to a system and method for PoE power mode policy and network management.
2. Introduction
In a PoE application such as that described in the IEEE 802.3af and 802.3 at specifications, a power sourcing equipment (PSE) can deliver power to a powered device (PD) over Ethernet cabling. Various types of PDs exist, including voice over IP (VoIP) phones, wireless LAN access points, Bluetooth access points, network cameras, computing devices, etc.
In accordance with IEEE 802.3af, a PSE can deliver up to 15.4 W of power to a single PD over two wire pairs. In accordance with IEEE 802.3 at, on the other hand, a PSE may be able to deliver up to 30 W of power to a single PD over two wire pairs. Other proprietary solutions can potentially deliver higher or different levels of power to a PD. A PSE may also be configured to deliver power to a PD using four wire pairs.
Conventional PDs are often hardcoded as to how much power that they will draw from the PSE switch. In this hardware-based classification scheme, the switch would determine whether it can fit this amount of power into its fixed total power budget. If this needed power can be accommodated within the PSE switch's fixed total power budget, then the switch will allocate the requested amount of power to the PD. In 802.3 at systems, Layer 2 mechanisms have been developed that enables dynamic power classification. This dynamic power classification is an improvement over hardware-based classification schemes and allows for the renegotiation of power between the PD and PSE. What is needed, however, is a mechanism that enables an IT manager to manage effectively a network of PDs.